Thursday, November 20, 2025

4:00 pm-5:00 pm

Understanding the fundamental exchange mechanisms of the strong force requires high-precision measurements of polarization observables across broad kinematic regimes. This colloquium presents a comprehensive look at the method used and kinematic reach of the latest eta-prime (η′) photoproduction study from the GlueX experiment. We focus on the measurement of the Beam Asymmetry (Σ) for the reaction γp → η′p. This key observable is highly sensitive to the naturality of the dominant t-channel exchange particles (such as the Rho(ρ) and Omega (ω) mesons). By utilizing a data set five times more extensive than prior work, we have doubled the accessible kinematic range in the four-momentum transfer (−t), allowing us to explore the reaction mechanism where it was previously unknown. The presentation will detail the methodology used to extract the asymmetry from azimuthal yield distributions, effectively reducing instrumental systematic effects. I will discuss the implications of these extended measurements for constraining theoretical Regge models. A preliminary result, in the previously unexplored t-range up to 1.7 GeV2, will be shown, demonstrating that the Sima (Σ) observable remains positive and close to unity, thereby confirming the persistence of the natural-parity exchange dominance.